Saitō Dōsan

Saitō Dōsan (斎藤 道三; 1494 – May 28, 1556), also known as Saitō Toshimasa (斎藤 利政), was a Japanese samurai lord and daimyo during the Sengoku period. He was also known as the "Viper of Mino" (美濃の蝮, Mino no Mamushi) for his ruthless tactics. He was appointed Governor of Yamashiro by the Imperial Court. After entering monkhood in his later years, he was also called Saitō Yamashiro-nyudō-no-kami (斎藤山城入道守).

He has historical reputation as one of Japan's Three Great Villains (日本三大梟雄), a nickname which he shared with Matsunaga Hisahide and Ukita Naoie, due to their ambitious and treasonous personality, along with the habit of resorting to underhanded tactics and assassinations to eliminate their opposition.